It's an insulated crimp terminal for wire sizes up to 16 gauge.
For instance on a power supply like a Meanwell or Megawatt, each screw terminal can accept 2 of these pins (one astride each screw) and there are 3+ positive and 3- negative terminals on each power supply. This six positive and six negative connections can be realized. Great for distribution networks and 6/16 gauge wires are roughly equal to a pair of 13 gauge wires or a solid 11 gauge which can handle serious current. Those power supplies use individual circuit traces to each output terminal. There is considerable volt drop involved at max output if only one terminal is utilized for each polarity.
